This application pertains to seeders and more particularly seeders which employ pressure activated plates, or trays.
It is well known in the prior art to apply a negative pressure to a backside of a seed sheet, or plate, to hold seeds to a front side of the sheet at holes therethrough and to then move the sheet to a planting position where the negative pressure is replaced by a positive pressure to release the seeds and deposit them in plugs in a plug tray. U.S. Pat. No. 3,627,173 to Kerker, for example, discloses a rather complicated automated, pressure-activated, seed-dispensing machine with which a pick-up element is moved from a first position to a second position for depositing seeds.
U.S. Pat. No. 4,573,609 to Tesch, on the other hand, discloses such a seed-planting apparatus which is primarily operated by hand. A difficulty with this device is that it is cumbersome, time-consuming and labor-intensive to use.
It is an object of this invention to provide a seeder apparatus which is relatively uncomplicated in structure and operation, and therefore is relatively inexpensive, but yet which can be operated at relatively great speeds with small expenditures of time and effort. In this regard, it is an object of this invention to provide such a seeder which can, to a large part, be operated by hand, but which requires a relatively small amount of physical effort on the part of an operator.
Further, it is an object of this invention to provide a seeder which, even though it can be operated at relatively great speeds, is highly accurate in operation allowing very small numbers of double plantings and/or failed plantings.